Jillian Jiggs to the Rescue

Jillian Jiggs wakes up one night to find her little sister Rebecca crying because she is afraid of monsters.With their usual creativity, Jillian and her friends use their problem-solving skills to help Rebecca deal with her fears: they decide to make a monster machine and set off on a monster hunt!

ISBN: 978-0439957809

Author: Phoebe Gilman